There are a variety of industrial applications which require the transport and/or processing of large volumes of material containing solids particulate. For instance, many coal burning facilities require the transport of large volumes of ash and related byproducts as part of the normal process of operation. In order to remove, process and/or transport such materials, it is common to use a conveyor system employing a chain, a belt or the like. A common component in systems for guiding and supporting such chains or belts (e.g., to facilitate a change in direction) is a component known as an idler wheel. Such wheels are often supported by a fixed, non-rotating shaft, and often are not directly driven by a motor or the like, though they need to maintain a specified rate of rotation to keep the belt or chain from breaking during operation. Thus, there is a need to know if the idler wheel is rotating to prevent damage or failure of the conveyor chain or belt.
Unfortunately, the operating conditions that are required of certain conveyance systems, such as the presence of fluids and/or corrosives which render direct observation of idler wheels impractical. Furthermore, the scale and operating location of certain conveyance systems may make localized observation impractical.
Presently available conveyor system technology includes the use of a rotation sensor embedded in the non-rotating shaft supporting the idler wheel. Such sensors can be used, for instance, to detect the rotation of a magnetic target plate mounted to the inside of the end cap that is bolted rigidly to the idler wheel. However, the use of such in situ sensor designs is that the sensor itself may be susceptible to a high rate of failure. Specifically, such sensors include the use of conductor wires extending from the non-rotating shaft during installation. In addition, the in situ sensor itself, as well as the sensor conductor wire, are particularly prone to failure in adverse operating conditions, such as high temperatures and/or corrosive environments.
Thus, the present state of the art reflects a need for a system which reliably detects and monitors the rotation of an idler wheel for a variety of conveyance systems and in various operating environments without requiring the use of in situ sensors and or other complex components with increased cost and failure risks.